Description: (Applicant's Description) The proposed Protein/Peptide Shared Resource has the broad goal of providing protein structure/function analysis for all SACI investigators. The completion of the "genome project" requires new strategies for examining expression levels of tens of thousands of transcripts, their products and their interactions. The Protein/Peptide Resource now has the capability to use mass spectrometry to analyze proteins separated by 2-dimensional gel electrophoresis. Identification of digests of individual protein spots can be made by database searching based on molecular weights and mass spectral fragmentation. Sequencing of novel peptides, verification of gene products, identification of post-translational modifications and determination of protein purity can also be readily accomplished. The Protein/Peptide Resource will continue to offer services such as traditional protein sequencing by Edman degradation chemistry, amino acid analysis, and peptide synthesis using the new Advanced Chemtech multiple peptide synthesizer, which has the capacity to produce 98 peptides at one time or gram amounts of a single peptide. New services added to the facility will include 2-D gel electrophoresis. Consultation and advice concerning protein chemistry, purification, and antibody production are provided upon request by SACI members.